Process of manufacturing erythrene hydrocarbons.



STATES PATENTQEFICE.

IWAN osTRoMIsLEN'sKY, or MOSCOW, ncssra PROCESS or MANUFACTURINGERYTHRENE izt szmto(masons.

No Drawing.

To all whom it may concern:

Be it known that'I, IWAN Os'rRoMIsLEN- SKY, doctor of philosophy, asubject of the Emperor of Russia, and a resident of Moscow, .Russia,have invented Processes of Manufacturing Erythrene Hydrocarbons, ofwhich the following is a specification.

The products of decomposition'of vapors of turpentine oil at a hightemperature were first examinedby Schulz in 1877 (Bem'chte derDeutschen, Oheme'schen Gesellsohaft, Volume X, page 113', year 1877). Itwas however only in 1882 that Tild-en succeeded in proving that whenpassing vapors of turpentine oil through an incandescent iron tube,isoprene is produced (Chemical 1V ews',

129, of 1882, J ommal of the American Okemiica'z'fiocz'ety 45, 910 of1884:- Jaha'esbericht iiber die Fortschm'tte'der Chem/5e 'zmdVereoandter Tez'le Anderer Wz'ssem'chaftealSSQ,

906. Compare Mokiewsky,0entmlblatf der Ohemie 1899 I, 589. Journal ofthe Russia-n Physic -C'hemical Society 30, 1889). Harries and Gottlobintroduced some improvements in the process, (Liebigs Annalen derUkemie, volume 383, page 190 year. 1911).-

Other improvements were introduced by Staudinger (Berta-hie derDeutschen Chemischen Gesellschaft year 1911, pages 2212, 22115) and bySilberrad. The authors in products from limonenes or dipentenes.Staudinger decom posed the vapors of the substances in question in avacuum of 2 mm. or in a current of a neutral gas. g

The process of Tilden as'carried out by Staudinger, is accompanied byconsiderable losses of isoprene. Isoprene under the circumstances is agas difiicult to. condense. The considerable unavoidable expenses forcooling the products of reaction, preclude the-possibility of anindustrial application of the process. It is further not very wellpossible in practice to work with apparatus which have a pressure onlyof 2-3 mm.

Substitution for the vacuum of a current of 'neutral gas according toStaudinger, is also not possible in practice. It would be necessary touse a considerable quantity of a neutral gas which is free from oxygen,for instance nitrogen. This would however considerably increase theexpense. On the other hand, the use of a gas current would bring about alarge loss of isoprene. In order to retain the isoprene carried away, itwould be necessary to use absorption sub- Specification of LettersIfatent. Patented Aug. 25', 1914:-

Application filed April 16, 1912. Serial No. 691,161.

stances suchas'bro-min. 'Thus,'the expense would be again considerably.increased.

According to Staudinger, the yield of: lsoprene with the use of a vacuum'or of a neutral gas current, from 'dipentenes or limonenes is increasedbyheating the vapors of l1 monene ordipentene in a dilu ted state, to hgh temperatures. In that way the decomposition and isomerization'ofisoprene,

which bring about losses whenthere is a strong concentration, areavbided. 1

According to experiments which led to the present process, when limoneneis boiled for a long time in a reflux cooler (boiling temperature about178 C.,) notonly heavy-oils are formed, but' also solid hydrocarbons,probably polyterpenes. "According" to the process, according to thisinvention, these reactions are avoided by heating thelimonene, dipenteneor turpentine oil,- not to the boiling point, but reducing the boilingpoint by adding liquids of a lower boilingv point.

The solvent added for dipentene and. limonene or turpentine oil can besolid or liquid at the ordinary temperature. It must be easily condensedand inust not act on the isoprene in the conditions of the reaction.

The solvent used must moreover not be perceptibly decomposed atua highertemperature.

Benzene can be .used as a solvent or its homologuesand polycycliccompounds such as naphthalene and the like." Thesolv'ent is heated toboiling, and vapors of the dissolved substance and of the solvent, are"exposed to the action of a, higher temperature, such as for instance ofan incandescent metal wire or of an incandescent wire netting. -90% ofthe theoretical quantity ofiso Iprene can be obtained.

When using a solvent which is solid'at "ordinary temperatures, 1t isadvisable, for the purpose of avoiding" choking the apparatus, to removethe products ofreaction in a continuous manner, and to provide theapparatus withsafety .valves and pressure gages.

Instead of making a solution of limonene or dipentene, the vapors can bebrought together separately. When the vapors are used separately,limonene ordipentene can be added to the Vapor of the solvent, such asbenzol, in front of the incandescent metal, and the relative quantity ofthe same could be regulated either by means of a drip funnel or by meansof any other suitable ap- Duration Tem era'- gig g m {3 m Jnopreno o!the twre o boil: chamber daphle obtained process. ingmlxture. withwmmater? I perminute.

45 Hours.

3.05 121 171 33 7 n 3.10 10s 17s ,as v e 3.30 103 169 31.5 6 50 s.40 115178 28.5 o

parat'u's. *Thejpro'cess coulil be also carried outby introducin.limonene or diperrten'e" .into a current of ea's'ily condensi'n'gsubstances which are solid or liquid at the ordinary temperature. Thetemperature selected must-be below the-boiling .point of the substances..l The mixture of the gases thencomes linto anincandescent metal tube,or

strikes metal wires' or wire. netting. When benzene is used as a meansfor dlluting,

vapors f of limonene or .dipentene .can be easily obtainedbetween 95 and115C.

The homologues \of dipentene' behave in a' similar. manner at a h ghertemperature.

Ihe hydrocarbon .is decomposed j unde'r the same conditions, formingdivinyli. This. hydroceilfbonwhich is a homologue of the .di'pente e'isobtained on heating divinyl v to 80-100 G. This observation has great j20 technical value, as polymerization of divinyl .into the simplestrubber takes place with formation of this hydrocarbon as by-product. Itis easyto'reconvert the same into divinyl'from which ;a new quantity ofrubber'is then obtained. i

Example: A mixture of 100 parts by volume of limonene (about 88 ms byweight) and 50 parts by volume 0% benzene (about 141 parts by weight)are heated in a a reflux cooler; (the temperature of the cooler about Inthe portionofi'the apparatus situated between" the supply for themixture and the cooler, apl'atinum wire one meter long is heated .todark red by an electric 35 current; I The cool'er 'isj'provided' with adephlegmator' as well as a thermometer and connected to another coolerfollowed by a receiver. I The followingresults have bee'n'obtained:

In the last experiments no "isbprefi'e a *ail was'pro'duced. This wasdue to the fact that no benzol remained in the tube of the refluxcooler. During the experiments mentioned below, the reaction tube wassurrounded with asbestos.

The above table shows that the speed of, reaction as well as the yieldof isoprene, are considerably increased when reducing the boiling pointof the original mixture: at a temperature of 104, 22 drops of isopreneare formed per minute, while at 115 only 16 drops,.and atll7 only 14drops. This :conclusion is sometimes rendered ,unclear by the action ofother factors.

What I claim is 1 A process of manufacturing an erythrene hydrocarbonfrom isomeric terpenes boiling at about 175 C, which consists inconverting the, raw material into a' vapor at a temperature lower thanthe normaLboiL ing temperature of the said raw material, by addingthereto some easily' condensed' and sufiiciently permanent compoundwhich is 11063; gas, at the normal temperature and heating the mixture,and then exposing the lvaporous mixture thus obtained to a hight,emperature.,-

In testimony whereof, I have signed ;name to this specification in thepresence of two subscribing witnesses:

i rWA os'rnoMrsLENsKY. Wiassfesgf a "'fVmSonirpno'r-p "Gm-(Emm-

